1. Field of the Invention
The present invention relates generally to a sensor and, in particular, to a system and method for implementing a control function via a sensor having a touch sensitive control input surface.
2. Background Art
In general, a scroll sensor is a sensor designed to convert the touch of an operator (i.e., user) into an input for an electronic device. Typically, scroll sensors are planar devices having the shape of a strip or a ring and may be implemented on the front face of a corresponding electronic device. Conventional scroll sensors are generally activated by touching and/or sliding an operator digit (e.g., finger) or an implement (e.g., stylus) on the surface of the sensor. The scrolling action may be linear, rotational, or along a more complex path.
Electronic devices that benefit from the utility of scroll sensors include, for example, cell phones, personal media players, portable gaming devices, computers, and cameras. Typically, the corresponding device has a display with a graphical user interface that may give feedback during scrolling actions. For example, the act of changing the volume on a music player might be indicated on a display by a moving bar whose length is proportional to volume.
An example of a portable electronic device with a single linear scroll sensor is the iRiver H10 mp3 player. Touching the sensor and moving or, in the alternative, touching the sensor at one end and holding accomplishes various actions such as song selection, volume control, etc.
An example of a portable electronic device with a rotary scroll sensor is the apple iPod. Touching the sensor and scrolling accomplishes various actions such as changing volume. The size of the change is generally proportional to the angular travel of the touch.
Conventional sensors implemented in connection with such electronic devices are not pressure sensitive. The present invention may add to the utility of sensors, such as the scroll sensor described above, by utilizing the added dimension of pressure.
A method of constructing a pressure sensitive resistive linear scroll sensor is described in U.S. Pat. No. 4,963,702 (assigned to Interlink Electronics Inc. and incorporated by reference in its entirety) which shows two orthogonal sensors layered to form a two dimensional touch pad.
A method of making a ring-shaped scroll sensor is described in U.S. provisional application No. 60/572,155 filed May 18, 2004 (incorporated by reference in its entirety), U.S. patent application Ser. No. 11/129,805 filed May 16, 2005 (incorporated by reference in its entirety), now U.S. Pat. No. 7,310,089.